ANNIVERSARY ADDRESS. 9 
pointed out to me evidence not only of the elevation of this 
coast, but also of its subsidence, and expressed his convic- 
tion that Port Jackson, Hawkesbury River, and other places 
on the coast, had been cut out by the action of fresh water, when 
the coast was much higher than it is at present—in fact, that 
these inlets had been at one time gullies exactly similar in cha- 
racter to those which now exist in the Blue Mountains, and which 
have been so obviously cut out by fresh water. Since that time 
many bridges have been made along the coast, and the borings 
made for foundations for these bridges have special significance in 
connection with Mr. Clarke’s opinion ; and by the kindness of the 
Engineer-in-Chief for Railways and the Engineer-in-Chief for 
Roads and Bridges I am able to quote here some of these mea- 
sures, which prove conclusively that the sea was at one time much 
lower than it is at present. The soundings taken for the Parra- 
matta railway bridge show 26 feet water, 32 feet mud and silt, 8 
feet loose sand, 12 feet hard sand, 10 feet loose sand ; total, 88 
feet. George’s River bridge—8 feet water, 87 feet mud and sand, 
9 feet black clay, 16 feet sand, 4 feet hard sand ; total, 121 feet. 
Hawkesbury River bridge—44 feet water, 31 feet light mud, 87 
feet black mud, 8 feet very hard sand; total, 170 feet. In the 
road bridge over the Parramatta River—41 feet water, 16 feet 
shells and mud, 15 feet sand, 9 feet blue clay, 6 feet clays and 
shells ; total, 87 feet. Ironstone Cove road-bridge—26 feet water, 
7 feet stiff blue clay, 36 feet very stiff blue clay, 15 feet yellow 
clay, 5 feet stiff black clay, 11 feet sand and clay, 2 feet clean 
sand, 3 feet gravel and wood ; total 105 feet. Shoalhaven River 
road-bridge—14 feet water, 103 feet mud and silt ; total, 117 feet. 
The bottom of the Hawkesbury, therefore, where the railway 
bridge is to be, is 170 feet below the level of the sea to-day ; and 
when the rocks were washed away to form the river-bed to that 
depth the sea must have been at least 170 feet below its present 
level, and the borings in Sydney Harbour and George’s River 
indicate a similar fact, if not to the same extent. 
Without going further into this question, which is foreign to 
my present purpose, I think I have said enough to show that the 
